Credit portal

How do you find derivatives

Calculus III (Math 3435)

Here are my online notes for my Calculus III course that I teach here at Lamar University. Despite the fact that these are my “class notes”, they should be accessible to anyone wanting to learn Calculus III or needing a refresher in some of the topics from the class.

These notes do assume that the reader has a good working knowledge of Calculus I topics including limits, derivatives and integration. It also assumes that the reader has a good knowledge of several Calculus II topics including some integration techniques, parametric equations, vectors, and knowledge of three dimensional space.

Here are a couple of warnings to my students who may be here to get a copy of what happened on a day that you missed.

Because I wanted to make this a fairly complete set of notes for anyone wanting to learn calculus I have included some material that I do not usually have time to cover in class and because this changes from semester to semester it is not noted here. You will need to find one of your fellow class mates to see if there is something in these notes that wasn’t covered in class.

In general I try to work problems in class that are different from my notes. However, with Calculus III many of the problems are difficult to make up on the spur of the moment and so in this class my class work will follow these notes fairly close as far as worked problems go. With that being said I will, on occasion, work problems off the top of my head when I can to provide more examples than just those in my notes. Also, I often don’t have time in class to work all of the problems in the notes and so you will find that some sections contain problems that weren’t worked in class due to time restrictions.

Sometimes questions in class will lead down paths that are not covered here. I try to anticipate as many of the questions as possible in writing these up, but the reality is that I can’t anticipate all the questions. Sometimes a very good question gets asked in class that leads to insights that I’ve not included here. You should always talk to someone who was in class on the day you missed and compare these notes to their notes and see what the differences are.

This is somewhat related to the previous three items, but is important enough to merit its own item. THESE NOTES ARE NOT A SUBSTITUTE FOR ATTENDING CLASS!! Using these notes as a substitute for class is liable to get you in trouble. As already noted not everything in these notes is covered in class and often material or insights not in these notes is covered in class.

Here is a listing and brief description of the material in this set of notes.

Three Dimensional Space

This is the only chapter that exists in two places in my notes. When I originally wrote these notes all of these topics were covered in Calculus II however, we have since moved several of them into Calculus III. So, rather than split the chapter up I have kept it in the Calculus II notes and also put a copy in the Calculus III notes. Many of the sections not covered in Calculus III will be used on occasion there anyway and so they serve as a quick reference for when we need them.

The 3-D Coordinate System We will introduce the concepts and notation for the three dimensional coordinate system in this section.

Equations of Lines In this section we will develop the various forms for the equation of lines in three dimensional space.

Equations of Planes Here we will develop the equation of a plane.

Quadric Surfaces In this section we will be looking at some examples of quadric surfaces.

Functions of Several Variables A quick review of some important topics about functions of several variables.

Vector Functions We introduce the concept of vector functions in this section. We concentrate primarily on curves in three dimensional space. We will however, touch briefly on surfaces as well.

Calculus with Vector Functions Here we will take a quick look at limits, derivatives, and integrals with vector functions.

Tangent, Normal and Binormal Vectors We will define the tangent, normal and binormal vectors in this section.

Arc Length with Vector Functions In this section we will find the arc length of

a vector function.

Curvature We will determine the curvature of a function in this section.

Velocity and Acceleration In this section we will revisit a standard application of derivatives. We will look at the velocity and acceleration of an object whose position function is given by a vector function.

Cylindrical Coordinates We will define the cylindrical coordinate system in this section. The cylindrical coordinate system is an alternate coordinate system for the three dimensional coordinate system.

Spherical Coordinates In this section we will define the spherical coordinate system. The spherical coordinate system is yet another alternate coordinate system for the three dimensional coordinate system.

Partial Derivatives

Limits Taking limits of functions of several variables.

Partial Derivatives In this section we will introduce the idea of partial derivatives as well as the standard notations and how to compute them.

Interpretations of Partial Derivatives Here we will take a look at a couple of important interpretations of partial derivatives.

Higher Order Partial Derivatives We will take a look at higher order partial derivatives in this section.

Differentials In this section we extend the idea of differentials to functions of several variables.

Chain Rule Here we will look at the chain rule for functions of several variables.

Directional Derivatives We will introduce the concept of directional derivatives in this section. We will also see how to compute them and see a couple of nice facts pertaining to directional derivatives.

Applications of Partial Derivatives

Tangent Planes and Linear Approximations We’ll take a look at tangent planes to surfaces in this section as well as an application of tangent planes.

Gradient Vector, Tangent Planes and Normal Lines In this section we’ll see how the gradient vector can be used to find tangent planes and normal lines to a surface.

Relative Minimums and Maximums Here we will see how to identify relative minimums and maximums.

Absolute Minimums and Maximums We will find absolute minimums and maximums of a function over a given region.

Lagrange Multipliers In this section we’ll see how to use Lagrange Multipliers to find the absolute extrema for a function subject to a given constraint.

Multiple Integrals

Double Integrals We will define the double integral in this section.

Iterated Integrals In this section we will start looking at how we actually compute double integrals.

Double Integrals over General Regions Here we will look at some general double integrals.

Double Integrals in Polar Coordinates In this section we will take a look at evaluating double integrals using polar coordinates.

Triple Integrals Here we will define the triple integral as well as how we evaluate them.

Triple Integrals in Cylindrical Coordinates We will evaluate triple integrals using cylindrical coordinates in this section.

Triple Integrals in Spherical Coordinates In this section we will evaluate triple integrals using spherical coordinates.

Change of Variables In this section we will look at change of variables for double and triple integrals.

Surface Area Here we look at the one real application of double integrals that we’re going to look at in this material.

Area and Volume Revisited We summarize the area and volume formulas from this chapter.

Line Integrals of Vector Fields Here we will look at a third type of line integrals, line integrals of vector fields.

Fundamental Theorem for Line Integrals In this section we will look at a version of the fundamental theorem of calculus for line integrals of vector fields.

Conservative Vector Fields Here we will take a somewhat detailed look at conservative vector fields and how to find potential functions.

Green’s Theorem We will give Green’s Theorem in this section as well as an interesting application of Green’s Theorem.

Curl and Divergence In this section we will introduce the concepts of the curl and the divergence of a vector field. We will also give two vector forms of Green’s Theorem.

Surface Integrals

Parametric Surfaces In this section we will take a look at the basics of representing a surface with parametric equations. We will also take a look at a couple of applications.

Surface Integrals Here we will introduce the topic of surface integrals. We will be working with surface integrals of functions in this section.

Surface Integrals of Vector Fields We will look at surface integrals of vector fields in this section.